Nemanja Vidic and Cristiano Ronaldo easily converted first-half headers but Masato Yamazaki pulled a classy goal back for the plucky Japanese side. Substitute Wayne Rooney bustled through to score with his first touch seconds later before Darren Fletcher nodded in. Rooney added a fifth though a late flurry saw Yasuhito Endo convert a penalty and Hideo Hashimoto fire home.Sir Alex Ferguson's side now face Liga de Quito in Sunday's final, while Osaka will meet Pachuca in the match for third place.
Critics question the credibility of a tournament where the gap in the team's ability appears vast - New Zealand's Waitakere United are only part-timers - but a thrilling end to this match, with six goals in the last 16 minutes, will at least arm Fifa with some positive ammunition.
Beforehand, Ferguson insisted his Champions League holders are determined to become the first British side to win it and the evidence was there in a strong starting line-up, though Dimitar Berbatov was absent through illness and Rooney started on the bench.
Yet reigning Asian Champions League winners Gamba Osaka gave as good as they got in a lively start, not looking like a side who had lost four of their past five games.
Source: BBC Sport